ACIS
ACIS DOSE Registered-Photon-Map
The steps we took to compute the dose map are;
- Level 1 Event files for a specified month are obtained from archive.
- Image data including I2, I3, S2, S3 CCDs are extracted from all event files.
- All the extracted image data were merged to create a month long exposure map for the month.
- The exposure map is opened with ds9, and check a distribution of count rates against energy. From this, estimate the upper threshold value. Any events beyond this upper threshold are assumed erroneous events such as bad pixels.
- Using this upper threshold, the data is filtered, and create a cleaned exposure map for the month.
- The exposure map from each month from the Sep 1999 is added up to create a cumulative exposure map for each month.
- Using fimgstatistic, we compute count rate statistics for each CCDs.
- For observations with high data drop rates (e.g., Crab nebula, Cas A), we corrected the observations by adding events.
Please check more detail plots at Telemetered Photon Dose Trend page.
Statistics: # IMAGE NPIX MEAN RMS MIN MAX ACIS_jun25 6004901 3.338 4.258 0.0 645 I2 node 0 262654 2.473845 1.765522 0.0 36.0 I2 node 1 262654 2.644616 2.117541 0.0 523.0 I2 node 2 262654 2.592687 1.784715 0.0 59.0 I2 node 3 262654 2.718883 1.920322 0.0 239.0 I3 node 0 262654 3.556177 2.175984 0.0 54.0 I3 node 1 262654 3.873597 2.305807 0.0 107.0 I3 node 2 262654 3.659864 2.206319 0.0 51.0 I3 node 3 262654 3.306851 2.048169 0.0 92.0 S2 node 0 262654 4.128091 3.610370 0.0 409.0 S2 node 1 262654 4.399498 4.032616 0.0 499.0 S2 node 2 262654 4.848449 4.424884 0.0 645.0 S2 node 3 262654 4.755714 4.108817 0.0 452.0 S3 node 0 262654 6.179419 3.947757 0.0 184.0 S3 node 1 262654 8.220650 4.370334 0.0 200.0 S3 node 2 262654 8.348629 4.545636 0.0 178.0 S3 node 3 262654 5.908524 3.061072 0.0 110.0
Statistics: IMAGE NPIX MEAN RMS MIN MAX ACIS_total 6004901 2736.538 3458.830 0.0 169725 I2 node 0 262654 2374.205460 482.341368 507.0 15805.0 I2 node 1 262654 2503.659076 708.356604 518.0 167719.0 I2 node 2 262654 2530.883569 537.539856 545.0 17500.0 I2 node 3 262654 2535.467967 659.271233 505.0 36336.0 I3 node 0 262654 2737.312529 679.072331 504.0 15342.0 I3 node 1 262654 2818.478455 1757.033546 529.0 56066.0 I3 node 2 262654 2526.463234 474.069777 495.0 15451.0 I3 node 3 262654 2503.074934 511.399344 473.0 36710.0 S2 node 0 262654 3193.769225 516.749553 1723.0 22647.0 S2 node 1 262654 3393.178754 775.301240 1895.0 21052.0 S2 node 2 262654 3763.587247 780.027450 2309.0 33834.0 S2 node 3 262654 3721.304797 637.967902 2032.0 86998.0 S3 node 0 262654 5661.912377 3066.764610 2489.0 55495.0 S3 node 1 262654 6876.429034 2408.007426 0.0 83602.0 S3 node 2 262654 5610.176685 1381.186157 2640.0 27686.0 S3 node 3 262654 4412.881089 782.803297 2656.0 26781.0
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The Mean Detrended CTI
We report CTIs with a refined data definition. CTIs were computed for the temperature dependency corrected data. Please see CTI page for detailed explanation. CTI's are computed for Mn K alpha, and defined as slope/intercept x10^4 of row # vs ADU. Data file: here
Imaging CCDs
Spectral CCDs
Backside CCDs
Focal Plane Temperature
Jun 2025 Focal Temperature
The Mean (max) FPT: | |
---|---|
-107.53 | +/- 7.69 C |
Mean Width: | |
0.8 | +/- 0.58 days |
Averaged Focal Plane Temperature
We are using 10 period moving averages to show trends of peak temperatures and peak widths. Note, the gaps in the width plot are due to missing/corrupted data.
Focal Plane Temperature, Sun Angle and Altitude
Bad Pixels
The plots below were generated with a new warm pixel finding script. Please see Acis Bad Pixel Page for details.
Front Side CCDs
Back Side CCD (CCD5)
Science Instrument Background Rates
Name | Low (keV) | High(KeV) | Description |
---|---|---|---|
SSoft | 0.00 | 0.50 | Super soft photons |
Soft | 0.50 | 1.00 | Soft photons |
Med | 1.00 | 3.00 | Moderate energy photons |
Hard | 3.00 | 5.00 | Hard Photons |
Harder | 5.00 | 10.00 | Very Hard photons |
Hardest | 10.00 | Beyond 10 keV |
HRC
DOSE of Central 4K Pore-Pairs
Please refer to Maximum Dose Trends for more details.
IMAGE NPIX MEAN STDDEV MIN MAX HRCI_06_2025.fits 16777216 0.049 0.224 0.000 12.000
IMAGE NPIX MEAN STDDEV MIN MAX HRCI_08_1999_06_2025.fits 16777216 na na na na
IMAGE NPIX MEAN STDDEV MIN MAX HRCS_06_2025.fits 16777216 0.018 0.197 0.000 21.000
IMAGE NPIX MEAN STDDEV MIN MAX HRCS_08_1999_06_2025.fits 16777216 na na na na
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Max dose trend plots corrected for events that "pile-up"
in the center of the taps due to bad position information.
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Gratings
Grating Trends/Focus
We plot the width of the zero order streak of ACIS/HETG observations and the width of the zero order image for HRC/LETG observations of point sources. No significant defocusing trend is seen at this time. See Gratings Trends pages.
PCAD
ACA Trending
ACIS |
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HRCI |
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HRCI |
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Fid Light Drift
Fid light positions on ACA drift with time. The drift trends of Fid light 2 with ACIS-I and ACIS-S configurations are shown below.
The top panel shows Fid light 2 drift in ACENT I (app. along with -Y axis), and the
bottom panel shows that in ACENT J (app. along with Z axis). The unit is a pixel, and
one pixel is approximately 0.5 arcsec. The slope listed at the top right corner is
the change in a position per year (arcsec/yr). The vertical line on DOM = 1411 (Jun 1, 2003)
indicates a transition date of use of IRU-1 to IRU-2.
See also Tom Aldcroft's updated page:
https://cxc.cfa.harvard.edu/mta/ASPECT/fid_drift
Fid 2 (ACIS-I)
Fid 2 (ACIS-S)
Fid 8 (HRC-I)
Fid 12 (HRC-S)
Gyro Bias Drift
Radiation History
Radiation Count Rates of Jun 2025
Sun Spot History (See:NOAA Page)

Trending
Critical Trends
ACIS Temperatures - Daily Maximums | |||||||
---|---|---|---|---|---|---|---|
MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
1pdeaat | 0.001 | 0.002 | (2.99+/-0.04)e2 | 1.24 +/- 1.33 | K | PSMC DEA PS A TEMP |
HRMA Computed Averages - Daily Maximums | |||||||
---|---|---|---|---|---|---|---|
MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
obaavg | -0.014 | 0.001 | (2.98+/-0.02)e2 | -1.27 +/- 0.65 | TEMP | OBA/TFTE |
EPHIN Temperatures - Daily Maximums | |||||||
---|---|---|---|---|---|---|---|
MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
teio | 0.026 | 0.009 | (3.30+/-0.22)e2 | 2.97 +/- 3.64 | K | EPHIN ELECTRONICS HOUSING TEMP | |
tephin | 0.008 | 0.003 | (3.39+/-0.08)e2 | 2.15 +/- 2.13 | K | EPHIN SENSOR HOUSING TEMP |
S/C Main Temperatures - Daily Maximums | |||||||
---|---|---|---|---|---|---|---|
MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
tcylfmzm | 0.020 | 0.004 | (3.13+/-0.10)e2 | 1.24 +/- 1.91 | K | CNT CYL TEMP:-Z SIDE UNDER LAE-1 | |
tcylfmzp | 0.020 | 0.004 | (3.16+/-0.09)e2 | 1.12 +/- 1.75 | K | CNT CYL TEMP:-Z SIDE UNDER LAE-2 |
S/C Ancillary Temperatures - Daily Maximums | |||||||
---|---|---|---|---|---|---|---|
MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
tfssbkt1 | 0.015 | 0.012 | (3.50+/-0.29)e2 | 3.75 +/- 4.12 | K | FSS BRAC | |
tfssbkt2 | 0.017 | 0.013 | (3.45+/-0.29)e2 | 3.80 +/- 4.17 | K | FSS BRAC | |
tsctsf1 | 0.004 | 0.002 | (3.24+/-0.05)e2 | 0.53 +/- 1.31 | K | SC-TS FITTING -1 TEMP | |
tsctsf6 | 0.003 | 0.002 | (3.24+/-0.05)e2 | 0.36 +/- 1.36 | K | SC-TS FITTING -6 TEMP |
MUPS - Daily Maximums | |||||||
---|---|---|---|---|---|---|---|
MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
pm1thv1t | 0.016 | 0.007 | (3.52+/-0.16)e2 | -1.18 +/- 2.51 | K | MUPS 1 THRUSTER VALVE 01 TEMP | |
pm2thv1t | 0.063 | 0.022 | (3.18+/-0.51)e2 | 0.41 +/- 7.55 | K | MUPS 2 THRUSTER VALVE 01 TEMP | |
pm1thv2t | 0.015 | 0.007 | (3.54+/-0.16)e2 | -0.79 +/- 2.65 | K | MUPS 1 THRUSTER VALVE 02 TEMP | |
pm2thv2t | 0.059 | 0.023 | (3.16+/-0.55)e2 | 1.27 +/- 8.00 | K | MUPS 2 THRUSTER VALVE 02 TEMP | |
pline02t | 0.023 | 0.005 | (3.36+/-0.12)e2 | 0.78 +/- 2.28 | K | PROP LINE TEMP 02 | |
pline03t | 0.025 | 0.006 | (3.29+/-0.14)e2 | 0.57 +/- 2.15 | K | PROP LINE TEMP 03 | |
pline04t | 0.023 | 0.005 | (3.17+/-0.11)e2 | 2.82 +/- 2.29 | K | PROP LINE TEMP 04 |
Quarterly Trends
- HRMA Struts
Previous Quarter | |||||||
MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
4rt584t | 0.005 | 7.523e-04 | (3.02+/-0.02)e2 | 1.21 +/- 0.40 | K | RT 584 - STRUT TEMP | |
---|---|---|---|---|---|---|---|
4rt585t | 0.005 | 7.450e-04 | (3.03+/-0.02)e2 | 1.26 +/- 0.39 | K | RT 585 - STRUT TEMP | |
4rt586t | 0.004 | 6.409e-04 | (2.98+/-0.02)e2 | 1.13 +/- 0.33 | K | RT 586 - STRUT TEMP | |
4rt587t | 0.003 | 4.826e-04 | (2.92+/-0.01)e2 | 0.85 +/- 0.24 | K | RT 587 - STRUT TEMP | |
4rt597t | 0.010 | 0.001 | (3.11+/-0.03)e2 | 1.76 +/- 0.82 | K | RT 597 - TFTE TEMP | |
4rt598t | 0.010 | 0.001 | (3.10+/-0.03)e2 | 1.46 +/- 0.82 | K | RT 598 - TFTE TEMP |
- OB Forward Bulkhead
Previous Quarter | |||||||
MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
4rt705t | 0.007 | 8.594e-04 | (2.93+/-0.02)e2 | 0.79 +/- 0.50 | K | RT 705 - OB BUL | |
---|---|---|---|---|---|---|---|
4rt706t | 0.007 | 8.687e-04 | (2.92+/-0.02)e2 | 0.84 +/- 0.51 | K | RT 706 - OB BUL | |
4rt707t | 0.007 | 8.628e-04 | (2.94+/-0.02)e2 | 0.67 +/- 0.51 | K | RT 707 - OB BULKHEAD TEMP | |
4rt708t | 0.008 | 9.395e-04 | (3.00+/-0.02)e2 | 0.78 +/- 0.55 | K | RT 708 - OB BULKHEAD TEMP | |
4rt709t | 0.008 | 0.001 | (3.01+/-0.02)e2 | 0.71 +/- 0.59 | K | RT 709 - OB BULKHEAD TEMP | |
4rt710t | 0.009 | 0.001 | (3.03+/-0.03)e2 | 0.81 +/- 0.63 | K | RT 710 - OB BULKHEAD TEMP |
- HRMA Thermal
- HRMA Thermal
Previous Quarter | |||||||
MSID | MEAN | RMS | DELTA/YR | DELTA/YR/YR | UNITS | DESCRIPTION | |
4rt568t | 0.006 | 9.319e-04 | (3.00+/-0.02)e2 | 1.26 +/- 0.53 | K | RT 568 - HRMA TEMP | |
---|---|---|---|---|---|---|---|
4rt569t | 0.002 | 2.987e-04 | (2.97+/-0.01)e2 | 0.64 +/- 0.12 | K | RT 569 - HRMA TEMP | |
4rt570t | 0.001 | 1.639e-04 | (2.96+/-0.00)e2 | 0.31 +/- 0.06 | K | RT 570 - HRMA TEMP | |
4rt575t | 0.008 | 0.001 | (3.06+/-0.03)e2 | 1.55 +/- 0.67 | K | RT 575 - OB CONE TEMP | |
4rt576t | 0.007 | 9.279e-04 | (2.96+/-0.02)e2 | 1.40 +/- 0.53 | K | RT 576 - OB CONE TEMP | |
4rt578t | 0.009 | 0.002 | (3.04+/-0.04)e2 | 1.66 +/- 0.87 | K | RT 578 - OB CONE TEMP |
Spacecraft Motions
TSC and FA Cummulative Moter Distance

HETG and LETG Cummulative Insertion Counts

HETG/LETG Insertion/Retraction Angle

Reaction Wheel Rotations
